Generation of a pulsed jet by jet vectoring through a nozzle with multiple outlets

ABSTRACT

A method of producing a pulsatile jet flow from a substantially constant flow primary jet in a way that is mechanically efficient, easy to implement, and allows direct control over pulse duration and pulsing frequency is disclosed herein. The invention includes at least two components: (a) a constant flow fluid jet produced by any normal method (e.g., propeller) that can be directionally vectored fluidically, mechanically, or electromagnetically and (b) a nozzle with multiple outlets (orifices) through which the vectored jet may be directed. By alternately vectoring the jet through different outlets, a transient (pulsatile) flow at an outlet is obtained even with a substantially constant primary jet flow. Additionally, the nozzle outlets may be oriented in different directions to provide thrust vectoring, making the invention useful for maneuvering, directional control, etc.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority to, U.S.patent application Ser. No. 12/726,826 filed Mar. 18, 2010, and claimspriority to U.S. Provisional Application Ser. No. 61/162,552, filed Mar.23, 2009, each of which is incorporated herein by reference in itsentirety.

TECHNICAL FIELD OF THE INVENTION

The present invention relates in general to the field of jet propulsionand thrust vectoring, and more particularly, to devices and methods thatprovide pulsatile jet flow from a constant jet flow.

STATEMENT OF FEDERALLY FUNDED RESEARCH

None.

REFERENCE TO A SEQUENCE LISTING

None.

BACKGROUND OF THE INVENTION

Without limiting the scope of the invention, its background is describedin connection with pulsatile jet flow.

Pulsed jets have found application in a variety of situations rangingfrom erosion and breaking of solid components in drilling applications(e.g., U.S. Pat. Nos. 4,607,792, 4,681,264, and 4,389,071) topropulsion. In studies related to propulsion, results for fixed/tetheredjets have shown that jet pulsation may be used to augment thrust overequivalent steady jets (Choutapalli, 2006; Krueger and Gharib, 2005).Additionally, studies of vehicles and aquatic animals propelled bypulsed jets have shown that short pulses producing isolated vortex ringshave higher propulsive efficiency than longer jet pulses (Bartol et al.,2008; Bartol et al., 2009); Nichols, et al., 2008). Thus, in a varietyof applications involving jet flow, it may be advantageous for the jetflow to be pulsed.

Numerous means for pulsing jet flows have been proposed and implementedin the scholarly and patent literature. One common method is to usetransient piston motion to effect jet pulsations. For example, a pistonsituated in a plenum (as in Krueger and Gharib, 2005) may move forwardin short steps to eject fluid slugs from a nozzle. Alternatively, thepiston may oscillate back and forth with the direction of fluid motiongoverned by check valves (as in Nichols, et al., 2008) so that forwardtranslation of the piston ejects a fluid slug from a nozzle while no netfluid motion occurs during piston retraction. Similarly, in U.S. Pat.No. 4,607,792 a liquid jet pulse is ejected into air by the forwardmotion of a piston and the plenum is recharged with liquid uponretraction of the piston. Cycling the piston motion generates a pulsedjet.

Another common method for creating jet pulses is to “shutter” a primaryjet. In U.S. Pat. No. 3,883,075, pressurized flow is directed to arotating nozzle block containing nozzles at fixed angular locationsaround the block. As the nozzle block is rotated, a jet pulse isreleased every time a nozzle aligns with the flow supply. Similarly,Choutapalli (2006) uses a spinning disk with holes to “chop” the flowsupply before it reaches the nozzle, resulting in interruptions to theflow and discrete jet pulses exiting the nozzle. An alternative valvingmechanism for generating jet pulses is described in U.S. Pat. Nos.4,077,569 and 4,863,101. In this method a pressurized flow source isdirected into a plenum with a specialized preloaded valve system inwhich the fluid pressure causes the valve to open, releasing a fluidpulse. When the pressure drops upon opening of the valve, the loading onthe valve induces it to close and the flow ceases until the cyclerepeats.

A further method for generating jet pulsations, described in Wilson andPaxson (2002) and in U.S. Pat. Nos. 5,495,903, 4,681,264, and 4,389,071,is to use specially shaped channels such as Helmholtz resonators, organpipes, or resonance tubes to establish and amplify natural fluidoscillations upstream of the flow exit. The resulting oscillations leadto jet pulsation at the flow exit.

An additional method for generating jet pulses is described in U.S. Pat.No. 6,868,790 and utilizes a combustion reaction to drive fluid out of anozzle in finite bursts of duration related to the burn time of thecombustion reaction.

In the prior art described above, the method of pulsation is either theprimary means for driving the flow (as with piston-operated pulsationmethods) or it is used in series with the primary flow (as in the caseswhere pulsation is achieved by interrupting the flow). None of themethods described above attempt to keep the primary flow steady(constant) while redirecting it to different nozzle outlets to generatejet pulses as described in the present invention. Generating jet pulsesby interrupting or inducing oscillations in the primary flow leads tolarge pressure fluctuations in the flow and/or requires large storageplenums to properly drive the flow. Using piston-displacement methods togenerate jet pulses tends to be inefficient as time and energy areexpended retracting the piston and/or refilling the plenum. Hence, inapplications such as propulsion it may be preferable to use the methodof the present invention so that the advantages of jet pulsation may begleaned while keeping the primary jet flow substantially steady, therebyallowing efficient and simple means such as ducted fans/propellers togenerate the primary flow.

An additional method for generating jet pulses using a valve mechanismis described in U.S. Pat. No. 4,267,856. The method utilizes a singlejet inlet and multiple jet outlets with a freely moving obstruction(typically a rubber sphere). The obstruction alternately blocks each ofthe outlets for a brief period, halting (and hence, pulsing) the flowfrom that orifice, but no method is provided for controlling thefrequency or duration of jet pulses.

U.S. Pat. No. 4,681,264 describes a method for generating jet pulsesusing a fluid oscillator valve. In this method, pulses are generated byalternately directing inlet flow to two different outlets using pressurefeedback loops connected to the primary flow conduit that direct theflow to the respective outlets in time intervals associated with thepropagation of pressure pulses through the loops.

SUMMARY OF THE INVENTION

The present invention includes at least two components: (a) a constantflow (steady) fluid jet produced by any normal method (e.g., propeller)that can be directionally vectored either fluidically (using the Coandaeffect, synthetic jets, counter flow, or other means), mechanically(using valves, vanes, or other means), or electromagnetically (usingelectric and/or magnetic fields to apply side forces to chargedparticles in the flow) and (b) a nozzle with multiple outlets (orifices)through which the vectored jet may be directed. By alternately vectoringthe jet through different outlets, the flow at an outlet will betransient (pulsatile) even though the flow of the primary jet issubstantially constant. The purpose of this invention is to producepulsatile jet flow from a substantially constant flow primary jet in away that is mechanically efficient, easy to implement, and allows directcontrol over pulse duration and pulsing frequency. Sufficiently shortjet pulses are known to generate compact vortical structures (vortexrings), which have been shown to augment thrust and propulsiveefficiency as compared to longer jet pulses and are useful in a varietyof marine or aerial propulsion applications. Additionally, the nozzleoutlets may be oriented in different directions to provide thrustvectoring, making the invention useful for maneuvering and directionalcontrol.

In one embodiment, the present invention is a vectored jet thrust devicecomprising: a substantially constant flow fluid jet whose downstreamtrajectory may be vectored at a multiplicity or a continuum of angleswith respect to the axis of the upstream flow; two or more fluidconduits in fluid communication with the jet; and a nozzle with one ormore outlets in fluid communication with the fluid conduits. In oneaspect, the constant flow primary jet is directionally vectoredfluidically, mechanically or electromagnetically such that pulsatileflow is emitted from the outlet(s) by alternately vectoring the jetbetween the available conduits. In another aspect, the primary jet isdirectionally vectored to the conduits fluidically by secondary controljets that generate a Coanda effect, secondary control jets that vectorthe primary jet by a momentum conservation effect, synthetic jets, orcounter flow. In another aspect, the jet is directionally vectored tothe conduits mechanically by valves or vanes. In yet another aspect, thejet is directionally vectored to the conduits electromagnetically by anelectric field, a magnetic field, or both. For example, a jet of chargedparticles is directionally vectored electromagnetically by an electricfield, a magnetic field, or both that apply side forces to chargedparticles in the fluid. In another aspect, exhaust from the nozzleoutlets comprise short jet pulses generated by alternately vectoring thejet between fluid conduits to generate compact vortical structures(vortex rings). The present invention may further comprise one or morefluid outlets in fluid communication with the fluid conduits capable ofbeing oriented in different angles relative to the upstream orientationof the jet to provide thrust vectoring, directional control, orpropulsion. In another aspect, the constant flow primary fluid jet isgenerated by a ducted fan/propeller, compressed air released through anozzle, a turbojet engine, jet engine, turboprop, ramjet, rocketpropulsion, and/or scramj et.

In another embodiment, the present invention is a system for vectoredjet thrust comprising: a device that generates a substantially constantflow fluid jet whose downstream trajectory is vectored at a multiplicityor a continuum of angles with respect to the axis of the upstream flow;two or more fluid conduits in fluid communication with the jet; and anozzle with one or more outlets in fluid communication with the fluidconduits, wherein the constant flow primary jet is alternately vectoredfluidically, mechanically, or electromagnetically to the fluid conduitssuch that the flow of the fluid exiting the nozzle outlet(s) variestransiently.

In yet another embodiment, the present invention is a method forvectored jet thrust from a jet comprising: generating a generallyconstant flow fluid jet whose downstream trajectory is vectored at amultiplicity or a continuum of angles with respect to the axis of theupstream flow; connecting the fluid jet to two or more fluid conduits influid communication with the jet; and positioning a nozzle with one ormore outlets in fluid communication with the fluid conduits, wherein theconstant flow primary jet is alternately vectored fluidically,mechanically, or electromagnetically to the fluid conduits such that theflow of the fluid exiting the nozzle outlet(s) varies transiently.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of thepresent invention, reference is now made to the detailed description ofthe invention along with the accompanying figures and in which:

FIG. 1. Examples of Mechanical Jet Vectoring: (a) Jet vectoring usingvanes, (b) vectoring using a movable protuberance in a speciallycontoured nozzle, and (c) vectoring using multiple conduits with valves.

FIG. 2. Examples of Fluidic Jet Vectoring: (a) Coanda-Assisted JetVectoring, (b) Synthetic-Jet Actuator Jet Vectoring, (c) Counterflow JetVectoring, and (d) Control Jet Actuated Jet Vectoring.

FIG. 3. Example of Jet Deflection Using Electromagnetic Actuation.

FIG. 4. Examples of Nozzles with Multiple Fluid Paths: (a) Two pathswith two outlets, and (b) two paths with one outlet.

FIG. 5. Generation of Pulsed-Jet Flow Using Coanda-assisted JetVectoring with a Dual-Output Nozzle. Jet flow exiting (a) output A, and(b) output B.

FIG. 6. Configurations for Thrust Vectoring: (a) Top View of a Nozzlewith Multiple Flow Paths and Different Jet Exit Angles for ThrustVectoring, (b) Isometric View of a 6-Orifice Nozzle for Thrust Vectoringin all Three Coordinate Directions.

FIG. 7. An Unmanned Undersea Vehicle (UUV) with 6-dof Control UtilizingVectored Pulsed-Jets on Each End.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts thatcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention and do not delimit the scope of theinvention.

To facilitate the understanding of this invention, a number of terms aredefined below. Terms defined herein have meanings as commonly understoodby a person of ordinary skill in the areas relevant to the presentinvention. Terms such as “a”, “an” and “the” are not intended to referto only a singular entity, but include the general class of which aspecific example may be used for illustration. The terminology herein isused to describe specific embodiments of the invention, but their usagedoes not delimit the invention, except as outlined in the claims.

As used herein the term “vectored jet” refers to a fluid jet whosedownstream direction may be altered from its upstream direction.

The term “nozzle” as used herein covers any conventional or preferredstatic mechanical devices used to direct or modify the flow of a fluid(liquid or gas). Nozzles are frequently used to control the rate offlow, speed, direction, mass, shape, and/or the pressure of the streamthat emerges from them.

The term “valves” as used herein encompasses devices that regulate theflow of a fluid (gases, liquids, fluidized solids, or slurries) byopening, closing, or partially obstructing various passageways. The term“vanes” as used herein refers generally to blades, shutters and otherplane or curved members.

The term “fluid jet” as used herein is intended to be broadly construedand includes, without limitation, high pressure fluid beam and should beread to include both jets made of liquid and jets made of vapor.

The term “fluid conduit” as used herein, includes both a closed conduit,such as a pipeline or other substantially tubular member, and an openconduit such as an aqueduct for transporting liquids such as water. Suchconduits may extend for tens, hundreds, or thousands of kilometers andmay be used to transport liquids, gases, slurries or other fluids.

The term “electric field” as used herein denotes the application of avoltage between two electrodes. The general term electric field thusdenotes a potential difference between the electrodes and may induce themotion of electric charge (current).

As used herein the term “magnetic field” refers to a random variable atleast partly representing said magnetic field, such as e.g. the modulusof the magnetic field or the magnetic field vector.

The term “propeller”, herein, refers to propulsion propellers andimpellers, such as for water propellers and for aircraft propellers(propulsion props, turbine blades, helicopter blades), as well as tostationary propellers and impellers used in high-power fans (windtunnels, high velocity fluid pumps) and stationary turbines. The term“jet engine” as described herein includes various types of engines whichtake in air at a relatively low speed and modifies itthermo-mechanically, and discharges the air at a much higher speed. Theterm jet engine includes, for example, turbo jet engines and turbo-fanengines.

As used herein the term “turbojet engine” is intended to encompass alljet engines employing a compressor, a combustor and a turbine forgenerating a high energy exhaust stream that is directed away from theengine to yield a reactive thrust component on the engine andconsequently on an airplane in which the engine is mounted.

The term “ramjet” is intended to include scramjets, where appropriate.Scramjet engines provide propulsion at hypersonic speeds (i.e., aboveMach 5) by capturing atmospheric air to burn onboard fuel. Forhypersonic propulsion, these air breathing engines are more efficientthan rocket motors and can allow longer duration hypersonic flight withgreater payload.

The term “hydrodynamics” as used herein refers to the study of liquidsin motion.

Fluid jets used for propulsion accelerate ambient fluid to create areaction force that propels the vehicle forward. Pulsing the flow usingdiscrete fluid pulses with little or no flow between pulses engendersthe formation of a vortex ring with each jet pulse. If the pulses areshort enough, isolated vortex rings are formed, but for longer jetpulses, the vortex ring will stop forming midway through the pulse andthe remainder of the pulse will be ejected as a quasi-steady jet (Gharibet al., 1998). For jet pulses short enough to produce isolated vortexrings, thrust is augmented and propulsive efficiency is improved (Bartolet al., 2008; Bartol et al., 2009); Krueger and Gharib, 2005). For thesereasons, it may be advantageous in certain propulsion applications touse a pulsed jet, but the jet pulsations must be produced in amechanically simple and efficient way in order for such an approach tobe practical. The present invention describes an apparatus, system, andmethod for producing a pulsed jet from a constant flow (steady) jet andcontrolling the duration and frequency of the resulting pulses using aspecially designed nozzle and a control mechanism for vectoring the jet.

The invention includes two primary components. The first component is asubstantially constant flow (steady) primary jet equipped with amechanism that allows it to be vectored through different angles offaxis from the original jet direction. The jet itself may be generated byany typical devices or methods for generating a steady fluid jet such asa ducted fan/propeller, compressed air released through a nozzle, aturbojet engine, jet engine, turboprop, ramjet, rocket propulsion,and/or scramjet. The jet vectoring mechanism may be mechanical, fluidic,or electromagnetic. Three examples of mechanical jet vectoringmechanisms are shown in FIG. 1. FIG. 1(a) illustrates jet vectoringusing directional vanes as described in Berrier and Re (1975). In thismethod, a constant flow jet (100) flows between directional vanes (101).By pivoting the vanes about hinges (102), the vanes may be deflected andthe direction of the jet altered. A second method illustrated in FIG.1(b) utilizes the method described in U.S. Pat. No. 5,060,867 forvectoring the jet angle. In this method, a constant fluid flow (200)passes through a contoured convergent-divergent nozzle (201). Thedivergent portion of the nozzle is contoured so that when a protuberance(202) is placed in the flow, the flow separates from the side with theprotuberance but remains attached to the opposite side, resulting in anattached jet flow (203) on part of a fluid conduit coupled to theconvergent-divergent nozzle. At the conduit exit, reentrant flow (204)enters opposite the attached flow and induces a low pressure thatdeflects the attached jet toward the reentrant flow as shown. By movingthe protuberance to another azimuthal location, the jet may be vectoredin a different direction. A third method for jet vectoring usingmechanical means is to use multiple valves and conduits as shown in FIG.1(c). In this method, constant flow (300) is directed through either oftwo or more conduits using valves (301). To direct the flow, one valveis open while the others remain closed. To direct the flow in a newdirection, a new valve is opened while all others are closed.

Examples of fluidic jet vectoring are shown in FIG. 2. TheCoanda-assisted method (FIG. 2(a)) is described in Allen and Smith(2009), Ward (2006), and Mason and Crowther, (2002). This methodutilizes a high velocity, low mass flux control jet (401) next to acurved surface (402) to induce a low pressure on the side of the controljet, leading the constant flow primary jet (400) to bend preferentiallytoward the side of the control jet. The angle of deflection iscontrolled by the ratio of mass fluxes of the two jets and the azimuthaldirection (top/bottom, left/right, etc.) is controlled by the azimuthallocation of the control jet. The synthetic jet actuator method (FIG.2(b)) is described in Smith and Glezer (2002) and uses a small, highfrequency synthetic jet (501) next to the constant flow primary jet. Therhythmic suction and pulsing produced next to the primary jet by thesynthetic jet induces a recirculation (entrainment) flow that causes theprimary jet (400) to bend toward the synthetic jet. Another example offluidic jet vectoring is the counterflow method, described in Strykowskiet al. (1996) and illustrated in FIG. 2(c). In this method suction (601)is used to pull fluid through a slot (602) next to the constant flowprimary jet, inducing the jet to deflect toward the suction slot. Afourth example of fluidic jet vectoring is the control jet methodintroduced in various forms in U.S. Pat. Nos. 3,204,405 and 3,740,003and illustrated in FIG. 2(d). In this method a control jet (701) isinjected into the constant flow primary jet (400) at an angle to thedirection of the primary jet. Momentum conservation of the combined jetsinduces the primary jet to deflect in the direction of the control jetas shown.

Electromagnetic systems may also be used to vector the jet if itcontains charged particles (as in the case of a plasma jet). An exampleof this method is illustrated in FIG. 3. In this case a constant flowcontaining charged particles (800) passes between electrodes (801). Theelectrodes may be biased with a voltage difference generating anelectric field (802) between them. The action of this electric field onthe charged particles imparts a tangential momentum to the jet particlesand deflects the jet to one side, similar to the control of the electronbeam in a cathode-ray tube (CRT). Alternatively, the electrodes (801)may be the ends of a U-shaped electromagnet (as described in U.S. Pat.No. 6,040,548, relevant portions incorporated herein by reference), inwhich case (802) is a magnetic field and the jet particles are deflected(vectored) off axis under the action of the Lorentz force.

The mechanical, fluidic, and electromagnetic methods for jet vectoringdescribed above substantially cover the methods used in the art, butderivatives of these methods or other jet vectoring methods known to onefamiliar with the art may also be applied to the present invention.

An example of the second component of the present invention is acontoured nozzle with multiple paths (conduits) for the flow to exit thenozzle. The usual method will be to use a nozzle with one flow inlet(901) multiple flow outlets (902) as shown in FIG. 4(a), but a nozzlewith one outlet and multiple flow conduits (903) may also be used (FIG.4(b)). When such a nozzle is joined together with a vectored constantflow jet, a pulsed jet is created by alternately vectoring the jetbetween available flow conduits in the nozzle. As an example, thecombination of a Coanda-assisted vectored jet with a two-output nozzleis shown in FIG. 5. The example embodiment shown in FIG. 5 uses ajet-pump impeller to generate the constant flow primary jet (1000) andthe location of the control jet (1001) determines the conduit throughwhich the primary jet flows. (A separate pumping mechanism, not shown,is required to generate the control jet in this embodiment.) When thecontrol jet (1001) is switched from side to side (cf. FIGS. 5(a) and(b)), the constant flow jet (1000) is alternately switched between thetwo nozzle outputs (1002 and 1003). When the flow is switched to a newoutput, the flow through that output is suddenly initiated and a fluidpulse is ejected. When it is switched back to the other output, the flowat the original output ceases while a new jet pulse is initiated at thecurrent output. The frequency of the pulsing is controlled by thefrequency of switching of the constant flow primary jet. Rapidlyswitching the flow between conduits produces short jet pulses resultingin isolated vortex rings (1004) for high efficiency or augmented thrust(high acceleration). Slower switching leads to longer jet pulses forsmoother operation while still producing a leading vortex ring with eachpulse that offers a propulsive benefit over a purely continuous jet.Similarly, decreasing the flow rate of the primary jet for a constantswitching (pulsing) frequency leads to shorter jet pulses whileincreasing the flow rate produces longer pulses. The ability to adjustthe flow rate of the primary jet provides access to a wide bandwidth ofspeed. Moreover, because the primary jet is constant flow, it may begenerated by any normal method and it may be produced under conditionsof optimal efficiency (e.g., an impeller optimized for the desired flowrate may be used in the embodiment shown in FIG. 5). Thus, the inventioncombines the advantages of jet pulsation with efficient means forproducing the jet flow. Note that for the valved jet vectoring methodshown in FIG. 1(c) to be utilized with the present invention in a mannerthat keeps the flow of the primary jet substantially constant, one valvemust always be open (i.e., pulsation is achieved by switching thelocation of the open valve, not by opening and closing valves).

FIG. 5 uses a nozzle with only two outlets. The invention may be easilyextended to a nozzle with any number of outlets, provided a sufficientlyversatile method for vectoring the jet to the different outlets is used.The invention may also be extended to use nozzles with contoured flowconduits exiting at different angles to effect thrust vectoring. Anexample allowing thrust vectoring is shown in FIG. 6(a) where vectoringthe constant flow primary jet (1100) to output (1101) or (1102) producesa jet exiting to the side, which may be used to generate a turning orstabilizing force. Alternately, vectoring between outputs (1103) and(1104), on the other hand, produces a pulsatile driving force useful forpropulsion, similar to that shown in FIG. 5. Other combinations may alsobe used, such as alternately vectoring the jet between outputs (1103)and (1101), which produces a pulsatile jet for propulsion (from output1103) and a pulsatile side force (from output 1101) for steering. Toachieve the level of vectoring control required for this arrangement,Coanda-assisted jet vectoring may be used, in which case the side onwhich the control jet (not shown) is used determines which pair ofoutputs (1103/1101 or 1104/1102) is accessible and the strength (massflow rate) of the control jet determines which output in a given pair isaccessed. For example, a strong control jet on the top side of theprimary jet (1100) in FIG. 6(a) would deflect the primary jet (1100) tooutput (1101), whereas a weaker control jet on the top would deflect theprimary jet (1100) to output (1103).

The hydrodynamics and propulsive performance of pulsed jets and vectoredjets are both well understood as separate units, but integrating the twointo a vectored pulsed-jet system and optimizing it for efficiency,maneuverability, station keeping, and stealth require careful design andtesting. The present invention includes a device, methods, and systemsfor a vectored pulsed-jet propulsion system that build on knowledge ofpulsed-jet propulsion and pulsed jet vectoring in, e.g., live squid andlaboratory tests of static pulsed jets.

Including additional orifices and vectoring the jet toward theselocations can provide control over additional degrees of freedom (dof)for directional control and station keeping. For example, with the6-outlet nozzle shown in FIG. 6(b), forward (+z) pulsatile thrust isachieved by alternating jet flow between outlets (1201) and (1202), apulsatile side force (−y) is achieved by alternating jet flow betweenoutlets (1203) and (1204), a pulsatile downward force (−x) is achievedby alternating jet flow between outlets (1204) and (1205), etc. Usingtwo nozzle/vectored-jet complexes on each end of a torpedo-styleUnmanned Undersea Vehicle (UUV) as shown in FIG. 7 can provide a 6-dofcontrol for agile maneuvering, station keeping, and vertical transportwhile still providing efficient cruise operation. In this configuration,the 6^(th) dof (roll) is obtained by including directional vanes (notshown) in orifices (1203), (1204), (1205), and/or (1206) of thenozzle/vectored-jet complexes (FIG. 6(b)) so the side jets, can bevectored azimuthally to create a rolling moment. Operation of thenozzle/vectored-jet complexes can be coupled with an inertial navigationsystem and a basic control system to allow the UUV to perform a varietyof maneuvers such as straight cruise, horizontal/vertical translation,and rotation about the pitch, yaw, and roll axes, etc. The inventiondescribed herein is unique from a fluid oscillator valve in that thepresent invention uses an independently controlled jet and fluidvectoring system that may control and vary the pulse frequency, pulseduration, and direction of the constant flow primary jet allowing forjet pulsing of arbitrary pulse frequency and duration and for thrustvectoring. In the usual embodiment of a fluid oscillator, the pulsingfrequency is fixed once the geometry of the feedback loop(s) is set andno method of control is provided. Embodiments of fluid oscillators thatdo provide control of pulse frequency and/or duration do not utilizeindependent control of the primary jet. Moreover, the present inventionallows for pulsatile jet flow to exit a multiplicity of nozzle outlets,while fluid oscillators only utilize two outlets. Hence, the combinationof a controlled jet vectoring system and multiple-outlet nozzle claimedin the present invention is unique and not an improvement readilyapparent to one skilled in the art.

It is contemplated that any embodiment discussed in this specificationcan be implemented with respect to any method, kit, reagent, orcomposition of the invention, and vice versa. Furthermore, compositionsof the invention can be used to achieve methods of the invention.

It will be understood that particular embodiments described herein areshown by way of illustration and not as limitations of the invention.The principal features of this invention can be employed in variousembodiments without departing from the scope of the invention. Thoseskilled in the art will recognize, or be able to ascertain using no morethan routine experimentation, numerous equivalents to the specificprocedures described herein. Such equivalents are considered to bewithin the scope of this invention and are covered by the claims.

All publications and patent applications mentioned in the specificationare indicative of the level of skill of those skilled in the art towhich this invention pertains. All publications and patent applicationsare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

The use of the word “a” or “an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean “one,” butit is also consistent with the meaning of “one or more,” “at least one,”and “one or more than one.” The use of the term “or” in the claims isused to mean “and/or” unless explicitly indicated to refer toalternatives only or the alternatives are mutually exclusive, althoughthe disclosure supports a definition that refers to only alternativesand “and/or.” Throughout this application, the term “about” is used toindicate that a value includes the inherent variation of error for thedevice, the method being employed to determine the value, or thevariation that exists among the study subjects.

As used in this specification and claim(s), the words “comprising” (andany form of comprising, such as “comprise” and “comprises”), “having”(and any form of having, such as “have” and “has”), “including” (and anyform of including, such as “includes” and “include”) or “containing”(and any form of containing, such as “contains” and “contain”) areinclusive or open-ended and do not exclude additional, unrecitedelements or method steps.

The term “or combinations thereof” as used herein refers to allpermutations and combinations of the listed items preceding the term.For example, “A, B, C, or combinations thereof” is intended to includeat least one of: A, B, C, AB, AC, BC, or ABC, and if order is importantin a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB.Continuing with this example, expressly included are combinations thatcontain repeats of one or more item or term, such as BB, AAA, AB, BBC,AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan willunderstand that typically there is no limit on the number of items orterms in any combination, unless otherwise apparent from the context.

As used herein, words of approximation such as, without limitation,“about”, “substantial” or “substantially” refers to a condition thatwhen so modified is understood to not necessarily be absolute or perfectbut would be considered close enough to those of ordinary skill in theart to warrant designating the condition as being present. The extent towhich the description may vary will depend on how great a change can beinstituted and still have one of ordinary skilled in the art recognizethe modified feature as still having the required characteristics andcapabilities of the unmodified feature. In general, but subject to thepreceding discussion, a numerical value herein that is modified by aword of approximation such as “about” may vary from the stated value byat least ±1, 2, 3, 4, 5, 6, 7, 10, 12 or 15%.

All of the compositions and/or methods disclosed and claimed herein canbe made and executed without undue experimentation in light of thepresent disclosure. While the compositions and methods of this inventionhave been described in terms of preferred embodiments, it will beapparent to those of skill in the art that variations may be applied tothe compositions and/or methods and in the steps or in the sequence ofsteps of the method described herein without departing from the concept,spirit and scope of the invention. All such similar substitutes andmodifications apparent to those skilled in the art are deemed to bewithin the spirit, scope and concept of the invention as defined by theappended claims.

REFERENCES

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What is claimed is:
 1. A method for vectored jet thrust of a vehicle,the vehicle defining three mutually perpendicular axes, the methodcomprising: generating a jet of substantially constant flow within thevehicle from an engine, wherein a downstream trajectory of the jet isvectored at one or more angles with respect to an axis of an upstreamportion of the jet; connecting the jet to at least two fluid conduits influid communication with the jet, the at least two fluid conduits beingwithin the vehicle, wherein the at least two fluid conduits are inalignment with the jet; and positioning at least one respective outletin fluid communication with each of the at least two fluid conduits,each respective outlet positioned on an outer surface of the vehicle andconfigured to exhaust at the outer surface of the vehicle, wherein fluidflow through each of the at least two fluid conduits is transientlyvariable by alternately vectoring the jet to each of the at least twofluid conduits, wherein exhaust at each of the respective outlets istransient while the jet is substantially constant, thereby providingvectored jet thrust, wherein the jet is alternately vectored to the atleast two fluid conduits fluidically by secondary control jets, andwherein the respective outlets are positioned such that the vectored jetthrust can be directed parallel to each of the three mutuallyperpendicular axes.
 2. The method of claim 1, wherein the secondarycontrol jets alternately vector the jet by: (a) Coanda-assisted jetvectoring, (b) using a momentum conservation effect, (c) synthetic-jetactuator jet vectoring, or (d) counter-flow jet vectoring.
 3. The methodof claim 1, wherein the exhaust from each outlet comprises short pulses,generated by the alternate vectoring of the jet between the at least twofluid conduits, which generate compact vortex rings, wherein a frequencyand a duration of the short pulses are independently controlled byvarying a flow rate of the jet and a frequency of vectoring between theat least two fluid conduits.
 4. The method of claim 1, wherein eachoutlet is capable of being oriented at different angles relative to theaxis of the upstream portion of the jet to provide thrust vectoring,directional control, or propulsion.
 5. The method of claim 1, whereinthe engine is a ducted fan/propeller, a turbojet engine, a jet engine, aturboprop, a ramjet, a rocket, or a scramj et.
 6. The method of claim 1,wherein the one or more angles with respect to the axis of the upstreamportion of the jet comprise a multiplicity or a continuum of angles.